Reflecting electric lamp.



A. DOUGLAS.

REFLEOTING ELECTRIC LAMP,-

APPLICATION FILED FEB. 19,19l7.

Patented. Apr. 9, 1918.

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HARRY A. DOUGLAS, OF BRONSON, MICHIGAN, ASSIGNOR T0 DOUGLAS & RUDD MFG. (30.,

OF BRONSON, MICHIGAN, A CORPORATION OF MICHIGAN.

REFLECTING ELECTRIC LAMP.

Specification of Letters Patent.

Patented Apr. 9, 1918.

Application filed February 19, 1917. Serial No. 149,666.

- tric Lamps, of which the following is a full,

clear, concise, and exact description.

My invention relates to reflecting electric lamps and has for its object the provision of improved means whereby the lamps may be cut in and out of circuit. In my invention there are included a shell constituting a holder and having a lamp bulb at its forward end and. a switching plug to. therear of the bulb, these parts being located in front of the casing that is a distinct element from the concave reflector, a. space intervening between the rear portions of the casing and reflector. 'A switching rod is preferably coupled with the switching plug and is operable from the exterior of the casing to enable the lamp to be switched in and out of circuit.

- In the preferred embodiment of the invention the switching is accomplished by turning the switching plug with reference to the shell in which event the W tching contacts are eccentric with respect to the shell so that they may be brought into and out of connection according to the movement of the plug. The bulb is desirably adjustable for focusing, etc. The rod may be pushed in and out to secure the focal adjustment, the bulb holding shell having sliding engagement with the holder that is carried by the lamp structure and which shell is held in adjusted positions by means of a spring structure exerting its pressure transversely of the shell.

I will explain my invention more fully by reference to the accompanying drawing showing the preferred embodiment thereof .Some part of the tongue, preferably the rear free end thereof, has a part 6 projecting therefrom which is narrower than the balance of the tongue and is slightly narrower than a slot 7 in the holder 3 whereby this portion may project into the slot to prevent the shell from turning with respect to the slot while at the same time the side margins of the tongue 4 are adapted to press against the side margins of the slot 7. The tongue thus presses upon a surface of the holder 3 and, where there is but one tongue, forces the shell toward the opposite side of the holder whereby the shell is held in engagement with the holder 3. The slot 7 is elongated so that the shell 5 may be moved forwardly and rearwardly in its holder 3 whereby in. the structure illustrated the position of the lamp bulb 8 which is carried by the forward end of the shell in front of the reflector may be focally adjusted with respect to the reflector. The base 9 of the lamp bulb 8 constitutes the forward contact carrier and as the arrangement illustrated is adouble pole arrangement this contact carrier 9 carries two rear contacts 10 and 11. The lamp base or contact carrier 9 is provided with bayonet pins (of which one 12 is shown) engageable within bayonet seats (of whichone 13 is shown) constituting parts of bayonet slots 14. The rear contact carrying plug'15 within the space between the rea portions of the casing and reflector is pro vided with terminal blocks 16 having bind ing screws 17 by which circuit wires may be secured to the terminal blocks. These terminal blocks are cylindrical and the forward ends thereof are tubular, springs (of which one 18 is shown) being included in the tubular portions of the terminal blocks and operof these contacts being within the back element. Thesprings 18 and the contacts 19 and 20 thus not only serve to establish cir- "ture thus far described in connection with theaccompanying drawing is disclosed and claimed in my co-pending application Serial No. 149,667, filed February 19, 1917.

The plug 15 is preferably rotatable within the rear end of the shell 5 in order that it may perform its switching function and when thus movably mounted it is desirably provided with bayonet pins (of which one 21 is shown) and which are receivable in alternate bayonet seats (of which a pair 22,-

23 is shown), the plug being desirably insorted from the front end of the shell with its pins passing along the bayonet slots 14 until they are in the zone that includes the bayonet seats 22, 23 whereafte'r the base of the lamp bulb is inserted inthe shell with its .pins 12 placed in the bayonet seats 13. The springs 18 thus not only serve to hold the bayonet pins 12 in the seats but also serve to hold the bayonet pins 21 in the seats to which they are adjusted. The construction of a connector comprising a shell and contact carriers at opposite ends thereof that are passed into the same end of the shell in assembling the parts of the connector is claimed. in my co-pending application, Serial No. 149,664, filed February 19, 1917. While I prefer to employ this construction in practising my present invention I do not wish to be limited thereto. I

It will be observed that the complemental switching contacts 10 and 19 are eccentric with respect to the shell as are also the complemental switching contacts 11 and 20 so that as the plug is turned these contacts are either brought into engagement or are separated according to the direction of movement of the switching plug 15. When the lamp is in open circuit the contacts 19 and 20 are pressed against the insulating portions of the lamp base that are adjacent the contacts 10 and 11. the springs 18 continuing to press the contacts 110 and 20 forwardly to maintain the bayonet pins upon the switching plug and upon the lamp base in their respective imyonet seats. The shell and the. parts within it are in front of the casing 2 and in order 'that the switching plug 15 may be turned with respect to the lamp base to cut the lamp in and out of circuit I employ a motion transmitting connection, preferably in the form of a forwardly and rearwardly movable and rotatable switching rod or mo tion transmitting element 24, which is connected at its inner end with (he switching plug (which is movable back and forth) and justment of the bulb. The particular form of lamp illustrated is what is known as a spot light but to whichform of lamp the invention is not to be limited. When the lamp is in the fq rm of a spot light the casing is provided with a handle 2 and this handle I preferably constitute a rearwardv .Lcontinuation of the casing, the switching rod Qtpassing through the handle to a point where it is operable from the exterior of the casing.

Any suitable means may be employed for establishing circuit relation between the contacts upon the plug 15 and the external source of eurrentpthere being illustrated a well known form of connector 15 which may be employed for this purpose.

In a reflecting electric lamp, the combination with a casing; of a reflector in front of the casing, a' space intervening between the rear portions of the casing and reflector;

an electric lamp bulb; a shell carrying the lamp bulb at its front and movable forwardly and rearwardly to effect focal adj ustment of the bulb; a contact carrying plug within the space between the rear portions of the reflector and the casing and coupled with the shell to be movable forwardly and rearwardly therewith in'the focal adjustment of the bulb-and serving to supply current to the lamp, the plug also being mounted to turn with respect to the shell to cut the lamp in and out of circuit, there being engageable and separable switching contacts in the lamp circuit, one upon the plug; and a forwardly and rearwardly movable and rotatable motion transmitting element HARRY A. DOUGLAS. 

